Exam II Microbiology: Chapter 5

Question 1

A fully formed virus that is able to establish an infection in a host cell

Answer 1

Virion

Question 2

Protein shell that surrounds the nucleic acid

Answer 2

Capsid

Question 3

The capsid together with the nucleic acid

Answer 3

Nucleocapsid

Question 4

Naked viruses consist only of a ___________; no outer membrane

Answer 4

Nucleocapsid

Question 5

Can be found on naked or enveloped viruses

Answer 5

Spikes

Question 6

External covering of a nucleocapsid, usually a modified piece of the host’s cell membrane

• Viruses take a piece of the cell membrane when they are released from a host cell.

Answer 6

Envelope

Question 7

• Single-stranded (ss)
• Double-stranded (ds)
• Linear
• Circular

Answer 7

DNA Viruses

Question 8

• Double-stranded, but more often single-stranded

must be copied into mRNA before translation can occur

Answer 8

RNA Viruses

Question 9

Ready for immediate translation (mRNA)

Answer 9

Positive single stranded RNA

Question 10

Must be copied into mRNA before translation can occur

Answer 10

Negative single stranded RNA

Question 11

+ ssRNA = ___________

Answer 11

mRNA

Question 12

Carry their own enzymes to create DNA out of RNA

Answer 12

Retroviruses

Question 13

What are the two different types of capsids?

Answer 13

1. Helical

2. Icosahedral

Question 14

What capsid structure is rod-shaped?

Answer 14

Helical

Question 15

What capsid structure is geometric in shape and made of 20 triangular pieces?

Answer 15

Icosahedral

Question 16

What capsid structure has an icosahedral head and many accessory structures that only infects bacteria and is designed to be able to punch through cell walls?

Answer 16

Complex

Question 17

What are the general phases of the animal viral replication CYCLE called?

Answer 17

The Lytic Cycle

Question 18

Viruses cannot bind to cells that lack _________ _________ ___________ ?

Answer 18

compatible virus receptors

Question 19

The entry of the virus through the plasma membrane (and for some cells the cell wall) and movement into the host cell is what part of the lytic cycle?

Answer 19

Penetration

Question 20

A condition in which the host chromosome carries viral DNA:

Answer 20

Lysogeny

Question 21

A virus can invade its host cell only through making an exact fit with a specific host molecule (receptor) on the surface of the cell is what part of the lytic cycle?

Answer 21

Absorption (Attachment)

Question 22

The release of nucleic acid through break down of capsid into cytoplasm of host cells is what part of the lytic cycle?

Answer 22

Uncoating

Question 23

Replication and protein production is what part of the lytic cycle?

Answer 23

Synthesis

Question 24

Which virus enters the host cell’s nucleus and replicates?

Answer 24

DNA viruses

Question 25

Messenger RNA’s for the viral proteins are made in the nucleus in which virus?

Answer 25

DNA viruses

Question 26

Viral proteins are made in the host cell cytoplasm in which type of virus?

Answer 26

DNA viruses

Question 27

Viral DNA enters the nucleus. If it is not already double stranded, host replication enzymes will make it double stranded in:

Answer 27

DNA viruses

Question 28

In the nucleus, viral genes are transcribed into a messenger RNA using host enzymes in:

Answer 28

DNA viruses

Question 29

Viral RNA and viral proteins are made in the cytoplasm in:

Answer 29

RNA viruses

Question 30

____ ______ usually bring in some viral enzymes since host cells are not able to replicate.

Answer 30

RNA viruses

Question 31

Viral RNA is converted to DNA using reverse transcriptase (a viral enzyme) in:

Answer 31

RNA viruses

Question 32

Viral DNA can insert into a host chromosome and become latent in:

Answer 32

RNA viruses

Question 33

Viral DNA can used in transcription and translation to produce viral RNA and viral protein in:

Answer 33

RNA viruses

Question 34

Virus is put together using “parts” manufactured during the synthesis process of the lytic cycle is called:

Answer 34

Assembly

Question 35

The virus leaves the host cell by two mechanisms in which process of the lytic cycle?

Answer 35

Release

Question 36

Which cycle produces a latent infection?

Answer 36

Lysogenic cycle

Question 37

Spongiform encephalopathies

Answer 37

Mad Cow Disease

Question 38

Virus-induced damage to the cell that alters its microscopic appearance

Answer 38

Cytopathic Effects (CPEs)

Question 39

Fusion of multiple host cells into single large cells containing multiple nuclei

Answer 39

Syncytia

Question 40

"Bacterial eating"

Answer 40

Bacteriophages

Question 41

Noncellular infectious agents are:

Answer 41

Viruses and Prions

Question 42

Periodically becomes activated under the influence of various stimuli • Herpes simplex and herpes zoster viruses

Answer 42

Chronic latent state

Question 43

Viruses incorporate into the DNA of the host. • This occurs in the lysogenic cycle of viral infection • Measles virus

Answer 43

Provirus

Question 44

When a bacterium acquires a new trait from its temperate phage

Answer 44

Lysogenic conversion

Question 45

1. Isolate and identify viruses in clinical specimens. 2. Prepare viruses for vaccines. 3. Do detailed research on viral culture, multiplication cycles, genetics, and effects on host cells.

Answer 45

Primary purpose of viral cultivation

Question 46

Specially bred strains of white mice, rats, hamsters, guinea pigs, and rabbits are the usual choices for:

Answer 46

Viral cultivation

Question 47

Chicken, duck, and turkey eggs are the most common choices for:

Answer 47

Inoculation

Question 48

Areas where virus-infected cells have been destroyed and show up as a clear, well-defined patches in the cell sheet:

Answer 48

Plaques

Question 49

- Infectious proteins - Agents of spongiform encephalitis infection - Deposited as long protein fibrils in the brain with no nucleic acid - Creutzfeldt-Jakob disease in humans - Bovine spongiform encephalopathy in cows - Found in many other animals as well

Answer 49

PRIONS

Question 50

- No immune response by the host (no antibodies) - Diagnosis by neural tissue biopsy - Fatal disease - No treatment - Infection is by eating contaminated meat or by exposure to the neural tissue of an infected animal

Answer 50

Spongiform encephalopathies (Mad Cow Disease)

Question 51

What cannot be inactivated by heat or other traditional methods of sterilization?

Answer 51

Prions

Question 52

Virus-like agents that parasitize plants are called:

Answer 52

Viroids

Question 53

What type of virus is composed of naked strands of RNA, lacking a capsid or any other type of coating?

Answer 53

Viroids

Question 54

What is the most common cause of human infections?

Answer 54

Viruses

Question 55

Most ______ ______ just slow down or prevent growth of the virus. They do not cure or completely eliminate the virus.

Answer 55

anitviral drugs

Question 56

What are the best approaches, at this time, to preventing viral infections?

Answer 56

Vaccines

Question 57

Mammalian viruses capable of initiating tumors

Answer 57

Oncoviruses

Question 58

What cancer does Papillomaviruses (HPV) cause?

Answer 58

Cervical cancer

Question 59

What cancer does Hepatitis B and Hepatitis C virus cause ?

Answer 59

Liver cancer

Question 60

What cancer does Epstein-Barr Virus cause?

Answer 60

Lymphomas

Question 61

What cancer does HIV cause?

Answer 61

Many types of cancer

Question 62

What cancer does HTLV-1 cause?

Answer 62

T cell leukemia

Question 63

What cancer does Human Herpes virus 8 cause?

Answer 63

Kaposi's sarcoma

Question 64

What cancer does Merkel cell polyomavirus cause?

Answer 64

Skin cancer